Buena Vista Lake Shrew - Brooke Lochhead

Buena Vista Lake Shrew (Sorex ornatus relicten)

By: Brooke Lochhead

Description and Ecology of the Organism

The Buena Vista Lake Shrew is an insectivorous ornate shrew weighing about the weight of a quarter and spending its days and nights in search of food. The small mouse-like creature has a long snout and a speedy metabolism requiring it to eat more than its body weight daily to survive. It is active day and night and is predominantly black with speckled brown spots and a grey belly only growing to about 4 inches in length. This cute little, unfortunately endangered creature gets its name from its home of the Buena Vista Lake in Kern County, however is found in a much wider span of California.The ornate shrews typically live about one year, breeding in February or March birthing about 4-6 young. Due to their short life-span, they must reproduce quickly in order to maintain populations leaving little time for error or complications with habitat etc. This species was first discovered in 1933, however little was recorded. Again in 1986, the Buena Vista Lake Shrew was rediscovered in the Kern Lake Preserve. In the 1990s, the status of the population was finally assessed and water management practices began at this time, not specifically for this particular mammal but for the wide variety of species affected by water levels in the ecosystem. Habitat loss and fragmentation commonly caused by water loss have had detrimental effects on the population of the Buena Vista Lake Shrew.

Geographic and Population Changes

Map of the Distribution in counties of the
Buena Vista Lake Shrew

 to the loss of marshlands and lakes in the Southern San Joaquin Valley, this shrew has declined in population from not only loss but fragmentation of habitat as well. These changes in habitat have separated the remaining few from each other and made them more susceptible to natural dangers such as fire and disease. As California allocates water elsewhere and experiences many dry years, the shrew’s habitat suffers leaving the mouse-like creature unfortunately vulnerable. The lakes and wetlands of California are commonly drained and converted into irrigated agricultural fields allowing lakes to fill only in years of larger amounts of rainfall which have been few and far in the past decade. The moisture is necessary for this shrew as it is required to support their prey, insects of a diverse abundance. This type of habitat also provides cover with commonly large willow trees or cottonwoods. The shrew's habitat changes have caused the population(s) to move habitat in search of riparian habitat elsewhere, leaving many vulnerable to potential extirpation or possibly even extinction in future years.

Listing Date and Type of Listing

The Buena Vista Lake Shrew was a Federal candidate for listing as threatened or endangered in 1998 and was listed as a California State Mammalian Species of Special Concern. The listing proposal was delayed until 2000 however and it was officially declared endangered in 2002. There were serious efforts in 2002 to designate protected habitat.

Cause of Listing and Main Threats to its continued existence

Buena Vista Lake, an example of the ideal riparian
 habitat for the Buena Vista Lake Shrew.

The shrew was listed due to the loss and fragmentation of habitat causing major decline and threats to its existence. Land is continuously converted for agricultural uses, especially in the Central Valley of California where this creature lives. The riparian habitat has declined heavily reducing the population to potentially a single population left.

Living in a restricted area of riparian land, the sole population is small and extremely vulnerable to changes to land made by humans. The land where this animal lives used to be managed by The Nature Conservancy, however due to a falling out, the J.G. Boswell Company no longer allows The Nature Conservancy to protect this land and creature. Without protection, the land continues to be converted for agriculture and with no other known populations outside the area, the species issusceptible to extinction.

Description of Recovery Plan

The conservation efforts currently include attempting to relocate the current population elsewhere and to attempt to locate other populations of the animal elsewhere. The current home of the shrew has no conservation agreement for the property or active management of the specie’s populations. The ideas of relocation include the Buena Vista Lake Aquatic Recreation Area, the Buena Vista Golf Course and along the Kern River due to their moist status and quality.

In 2005, 84 acres were designated as critical habitat, which was nowhere near the desired amount. However, in 2009 a proposed 5,182 acres of critical habitat revised this designation. These acres include private and public lands and prohibits individuals from engaging in unauthorized activities that harm listed wildlife. The estimated economic impacts of this critical habitat designation were approximately $133,000. This critical habitat helps the shrew to reproduce safely in the moist, safe environment that it desires.

What can you do?

The Center for Biological Diversity works extensively to protect this creature through lawsuits, projects and extensive work to ensure the protected habitat remains protected. This organization works nonstop to save wildlife and encourages wildlife enthusiasts to give monthly to keep our wildlife populations diverse and here on earth. Here is the link to their website to learn more about what they do, how to donate and where your money goes in action to helping our favorite wildlife creatures like the ornate shrews!

https://www.biologicaldiversity.org/action/index.html

Another great way to help that doesn’t include financial bindings is by demanding action through messages to decision makers. A simple letter may seem small, but when hundreds of people are nagging a lawmaker about an issue, there is much more likeliness that something will be changed. Through attending public meetings, making phone calls and staying knowledgable about issues such as the habitat loss of the Buena Vista Lake Shrew, we can make a difference as citizens. To watch one’s own actions is another method to help, especially as we often destroy our wild lands without even knowing it.

The small, adorable long-nosed creature needs our help to maintain and grow the small population that is left and with simple actions, we can keep the protected land alive to allow the precious little shrew to reproduce and eventually prosper!

Other Resources

Citations

 “Buena Vista Lake Shrew.” Center for Biological Diversity, www.biologicaldiversity.org/species/mammals/Buena_Vista_Lake_ornate_shrew/index.html.

 “Buena Vista Lake Ornate Shrew (Sorex Ornatus Relictus).” U.S. Fish & Wildlife Service, ecos.fws.gov/ecp0/profile/speciesProfile?spcode=A0DV.

“Endangered Species Recovery Program.” 6. Buena Vista Lake Shrew (Sorex Ornatus Relictus), esrp.csustan.edu/publications/pubhtml.php?doc=sjvrp&file=chapter02M06.html.

Service, U.S. Fish and Wildlife. “U.S. Fish and Wildlife Service.” Official Web Page of the U S Fish and Wildlife Service, www.fws.gov/.

Image Sources (in order of appearance)

https://en.wikipedia.org/wiki/Ornate_shrew

http://esrp.csustan.edu/publications/pubhtml.php?doc=sjvrp&file=chapter02M06.html

https://playingbakersfield.wordpress.com/2013/05/10/buena-vista-lake-offers-some-fun-in-the-sun/